Field of the Invention
Embodiments of the present invention generally relate to a stabilizer.
Description of the Related Art
Stabilizers have been used to support a drill string during a drilling operation. The stabilizers have a larger outside diameter than the drill collars and are in constant rotational contact with the sidewall of the wellbore during the drilling process. The problem with stabilizers is that the contact between the stabilizer and the wellbore can be the source of many problems. For example, penetrated, soft formations may collapse or swell inwardly after penetration of the bit which may in turn cause the stabilizer to become stuck. In addition, the stabilizer may become stuck during retrieval, such as hanging up on a ledge or a “dune” of cuttings.
Freeing a stuck pipe generally requires tremendous effort and time. Often the drill string and expensive bottom hole drilling/measurement tools must be left downhole and the wellbore re-drilled.
There is a need therefore, for a stabilizer that is capable of being selectively collapsed to reduce its outside diameter if the stabilizer becomes stuck.